The New BRC-721E

The New BRC-721E Token Standard: Migrating Ethereum NFTs to Bitcoin

Soon after the BRC-20 token standard became popular and jumpstarted its own memecoin season, BRC-721E emerged. The introduction of the BRC-721E token standard allows users to bridge NFTs from Ethereum to Bitcoin, an innovation that opens the possibility of cross-chain interactions and allows for NFTs to migrate to the Bitcoin network.

BRC-721E tokens came out of a collaboration between Bitcoin Miladys, Ordinals Market, and Bitcoin wallet Xverse. Miladys are a popular, anime-inspired profile picture (PFP) NFT collection on Ethereum, and the first BRC-721E non-fungible token bridged from Ethereum became a Bitcoin Milady.

What is a Bridge and How Does BRC-721E Work?

A blockchain bridge (or cross-chain bridge) allows users to transfer digital assets and data between two different blockchain networks. The goal of the BRC-721E token standard is to bridge NFTs from Ethereum to Bitcoin and, as we mentioned previously, migrate Ethereum NFTs to Bitcoin.

“Tele-burning” NFTs onto Bitcoin in an Ordinal Inscription

First, users need to send their ERC-721 token on Ethereum to a burn address. Then, they need to mint the NFT on Bitcoin using Ordinals inscriptions, which they can do via the Bitcoin Milady Bridge. This process prevents duplicate NFTs because once the Ethereum token is burned, it’s considered bridged to Bitcoin.

Currently, BRC-721E tokens inscribe a less detailed version of the NFT on Bitcoin with a link to the original Ethereum token. It is possible, however, that the token standard will evolve to allow full metadata in the future.

BRC-721E Features and Benefits

After users bridge an NFT to Bitcoin, it will automatically appear on Ordinals Market, a popular Ordinals marketplace that has emerged as a key player in the Bitcoin NFT market. NFT listings on Ordinals Market have comprehensive metadata, giving NFT holders the information they need in a transparent way.

Other features include airdrop capability, allowing users to receive BRC-721E airdrops. Bridging NFTs to Bitcoin also reduces the costs of transferring NFTs.

Why is NFT Migration Between ETH and BTC Important?

Just like Ordinals and the BRC-20 token standard, bridging NFTs from Ethereum to Bitcoin opens new possibilities. Many people still hold the belief that Bitcoin is mostly suitable only as a medium of exchange or store of value. With new and innovative protocols getting implemented on the world’s largest blockchain, more users are coming to the network.

Creating fresh ways to make blockchains interoperable also moves us closer to the multi-chain world so many dream about. By June 2023, more than 10 million Ordinals had been inscribed on Bitcoin. And despite a dip in inscription volume during the second half of May, BRC-721E bridging NFTs from Ethereum to Bitcoin promises to bring more excitement as more users experiment with the interoperability that comes with moving assets from Ethereum to Bitcoin.

However, it’s important to note that moving NFTs from Ethereum to Bitcoin is a permanent, one-way transaction. Because you send the ERC-721 token to a burn address, it’s unrecoverable.